Self-retaining sutures (sometimes referred to as “barbed sutures”) are known, and these sutures are quite helpful in providing secure holding of tissue in various procedures. Self-retaining sutures generally are sutures that have a plurality of retainers, or barbs, on their outer surfaces. In some sutures, these retainers are formed by cutting into the outer surface of a suture to a desired depth and angle, forming a cut portion, which remains secured to the suture at its base. This cut portion typically has a pointed end, which catches tissue when pulled in an opposite direction.
Devices for forming self-retaining sutures are also known, including, for example, those described in U.S. Pat. No. 6,848,152 and U.S. Pat. No. 8,615,856. Apparatuses include, among other features, a device to feed a length of suture through a cutting apparatus, and a blade that intermittently cuts into the suture. In devices, such as that of U.S. Pat. No. 8,615,856, the blade rotates around a central axis, where it cuts into the outer surface of a suture at regular intervals.
During use, as the blade is repeatedly cut into sutures, the blade's configuration may change. For example, the blade may become dull, or it may become heated and warped. Further, although the blade is held securely in place, over use, the blade's position may shift. In addition, the blade may need to be changed repeatedly, and the user may not position the new blade perfectly. Even slight warping or shifting can cause the blade to cut the suture in undesired fashions. As such, it is helpful to have a device and method that can monitor the blade's position and configuration, alerting a user to defects or even controlling the blade position to account for defects.